Since the beginning of July, St James's Street has been two-way. This scheme has been introduced as part of Westminster's Piccadilly two-way project.
As a result of the two-way scheme, there is now a shorter route from Old Bond Street to the Mall, shown in blue on the map. The old route, shown in red, went around St James's Square and was about 400 metres longer.
You may be wondering why you cannot follow an even shorter route by turning right from Old Bond Street into Piccadilly and then left into St James's Street. This is because the central reservation of Piccadilly blocks the right turn from Old Bond Street.
When we referred this problem to Transport for London, we were told "It was not possible to design a scheme for Piccadilly which allows right turns from Old Bond Street without causing considerable traffic queues and conflict with pedestrian crossing points."